Commonly punch presses are employed to punch holes in metal sheet and plate and, for this purpose, most punch presses comprise a C-shaped frame having a punch head assembly adapted to reciprocate the punch in a vertical direction to co-operate with a die over which the sheet or plate to be punched is positioned. Many such presses employ crank drive arrangements to cause reciprocation of the punch. However in such arrangements the stroke of the punch cannot be varied easily, for example to cater for varying material thicknesses. Furthermore, the noise generated by such press arrangements during punching is relatively high.
It is also known to drive punching tools by hydraulic means, for example by reciprocating pistons. Whilst in this arrangement the stroke of the punch can be varied, noise generation still remains a problem. Additionally, hydraulic drives are not normally adapted for rapid punching of thin plate as well as for punching thicker plate.